Apparatus for teeming degassed molten metal



1, 1967 H. F. SHEKELS APPARATUS FOR TEEMING DEGASSED MOLTEN METAL Filed July 29, 1964 Fla "1 MI l/E/V TORS HAROLD FT SHEKEL 5 f g A Wamw United States Patent Ofifice 3,333,626 Patented Aug. 1, 1967 3,333,626 APPARATUS FOR TEEMING DEGASSED MOLTEN METAL Harold F. Shekels, Edgewood, Pa. (150 Race St., Pittsburgh, Pa. 15218) Filed July 29, 1964, Ser. No. 385,879 3 Claims. (Cl. 164-254) The present invention relates generally to the art of teeming molten metal and, more particularly, has as its primary object the provision of an improved apparatus for teeming degassed molten steel.

It is another object of my invention to provide a novel and unique vacuum apparatus which may be installed on a conventional molten-metal ladle and be carried thereby for degassing molten metal as it is teemed from the ladle.

It is a further object of my invention to provide vacu um apparatus of the character set forth by the object immediately above which may be optionally operated to effect degassing of all or of only portions of the molten metal teemed from the ladle.

These and other objects will become more apparent after referring to the following specification and attached drawing, in which:

FIGURE 1 is a front elevational view, partly in section, of a molten-metal ladle equipped with a degassing apparatus in accordance with the invention; and

FIGURE 2 is a cross-sectional view taken along the line IIII of FIGURE 1.

Referring more particularly to the drawing, reference numeral 2 designates a molten-metal ladle having a pouring nozzle 4 projecting from its bottom and a stopper-rod 6 in operative association with the nozzle for opening and closing the same, as understood in the art.

An insulated, dished-bottom vacuum chamber 16 having a filling neck 18 projecting upwardly from its top is suspended below the bottom of the ladle with the filling neck 18 telescoped over the pouring nozzle 4 of the ladle. Four spaced electronic load cells 8 are rigidly mounted on and project upwardly from the top of the chamber 16 and are attached to the ladle bottom by means of aligned heavy metal eyes 10 and 12 detacha-bly secured together by nut and bolt means 14. The eyes 10 are welded or otherwise rigidly afiixed to the ladle bottom and a bracket extension 2 thereof and hang down therefrom, while eyes 12 are rigidly attached to the load cells and project upwardly therefrom.

A substantially cylindrical collar 20 made of a flexible, heat-resistant material, such as asbestos or the like, is disposed around the telescoped neck 18 and nozzle 4. The inside diameter of the collar 20' is slightly greater than the outside diameter of the neck 18; but, when the chamber 16 is evacuated as will be hereinafter described, the collar 20 is drawn tightly against the telescoped filling neck and nozzle by the vacuum pressure created inside the chamber so that it functions to provide an air seal around the junction of these members.

The vacuum chamber 16 and its filling neck 18 are provided with a refractory lining 22 and an outer heatinsulating cover 24. The outer surface 'of the ladle bottom above the vacuum chamber and the electronic load cells is provided with a similar heat-insulating cover 26 to protect the load cells.

A ceramic discharge nozzle 28, surrounded by a protective metal sleeve 29, depends from the bottom of the vacuum chamber 16 and is provided adjacent its exit end with a stopper valve 30 for controlling the flow of molten metal through the nozzle. Valve 30 is of the general type disclosed by Patent No. 1,742,065.

A vacuum exhaust line 32 extends upwardly from the vacuum chamber 16 to a connection with a dust catcher 34 containing baflle plates 36. Dust catcher 34 with the baffle plates 36 serves to remove any solids, such as particles of solidified metal, that may be present in the air exhausted from the vacuum chamber while it is being evacuated. A vacuum line 38 extends from the dust catcher 34 to a vacuum pump 40 which is mounted on a ledge or shelf 42 which, in turn, is attached to and extends laterally from the outer wall of the ladle 2 above the vacuum chamber 16. The vacuum pump 40 is connected with and driven by a gas turbine 44 which is also mounted on the shelf 42.

In operation, to teem degassed steel into an ingot mold M after molten steel has been poured into the ladle 2from the runner of an open hearth furnace or from another ladle, ladle 2 is suspended from the lift'hooks H of an overhead crane (not shown); and gas turbine 44 is actuated to operate the vacuum pump 40 to exhaust air from vacuum chamber 16 and effect its evacuation. While the vacuum pump continues to operate, stopper-rod 6 is manipulated by the crane operator to open pouring nozzle 4 to permit molten steel to pass from the ladle into vacuum chamber 16; and the ladle is transported by the overhead crane to a position over the ingot mold M, which may be the first in a series of ingot molds into which the molten steel is to be teemed. Then, after the vacuum chamber 16 has been approximately half filled with molten steel, stopper valve 30 is opened to cause the degassed molten steel to flow into the ingot mold M from the discharge nozzle 28. The pouring nozzle 4 of ladle 2 is kept open while the ingot mold is being filled so as to maintain vacuum chamber 16 always approximately half filled with molten steel. This insures that no air will be drawn up into the vacuum chamber through the nozzle 28. After the ingot mold M has been filled, the stopper valve 30 is closed by a pouring pit workman; and then the stopper-rod 6 is manipulated by the crane operator to close pouring nozzle 4.

The electronic load cells 8, which may be of any suitable type available on the market, such as the model designated Type TXX and manufactured by Streeter-Amet Company, of Chicago, Ill., are connected by means of heat-insulated lead wires L with an indicator scale (not shown) located in the operating cab of the overhead crane. By observing the indicator scale, the crane operator knows how much molten steel, by weight, is in the vacuum chamber 16 at all times. Proper manipulation of the stopper-rod by the crane operator, in conjunction with the operation of the stopper valve by the pouring pit workman, maintains the molten steel in the vacuum chamber at the desired level.

Although I have shown the vacuum chamber 16 suspended with four electronic load cells, it will be understood that more or less than this number can be used, as desired.

After ingot mold M has been filled, the crane moves the ladle to the next ingot mold; and the stopper-rod and stopper valve are again operated to teem the degassed molten steel into the mold.

It will be noted that discharge nozzle 28 must be relatively long, viz., at least sixty inches, to permit the degassed molten steel to flow and a vacuum seal to be maintained. However, if desired, a relatively-short discharge nozzle (not shown) may be used if an inert gas is bled into the vacuum chamber to break the vacuum and permit the molten steel to flow normally.

If desired, the degassing apparatus of the invention may be operated while only a portion of the molten steel in the ladle is teemed. When degassed steel is not required, the gas turbine and vacuum pump are not operated while the molten steel flows from the ladle into the vacuum chamber and then through the nozzle 28 into the ingot mold.

It will now be obvious that any conventional moltenmetal ladle can be readily converted into a mobile degassing ladle unit in accordance with my invention. It will be further "obvious that a ladle thus converted can be'quickly and easily returned to its original form and mode of functioning by removing the apparatus of the invention therefrom.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. The combination, with a ladle for teeming molten steel, which ladle includes side and bottom walls, a pouring nozzle in said bottom wall, and a stopper for controlling fiow through said nozzle, of a vacuum degassing apparatus comprising a plurality of support means depending from said ladle, respective load cells depending from said support means and being detachable therefrom, a refractory lined chamber carried by said load cells beneath said ladle and having a filling neck at its top telescopically receiving said nozzle, flexible means providing a seal between said nozzle and said neck, a nozzle extending downwardly from said chamber, means in said second-named nozzle for controlling flow therethrough, a vacuum pump and a drive therefor, support means on the side wall of said ladle above said chamber on which said pump and drive are mounted, and a vacuum exhaust line extending downwardly from said pump into said chamber, said apparatus being supported eX- clusively from the walls of said ladle to enable the ladle and apparatus to be moved freely about as a unit in all directions, said load cells transmitting a continuous indication of the weight of material in said chamber.

2. A combination as defined in claim 1 in which said secondnamed support means includes a shelf projecting from the side wall of said ladle.

3. A combination as defined in claim 1 further comprising a dust catcher in said vacuum exhaust line between said pump and said chamber, and baffies in said dust catcher.

References Cited UNITED STATES PATENTS 1,409,003 3/ 1922 James 222--77 2,085,450 6/1937 Rohn 2273 2,190,209 2/ 1940 Hazey 22--73 3,058,621 10/1962 Stenzel 2279 3,146,288 8/1964 Gero 2273 FOREIGN PATENTS 801,519 9/ 1958 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner.

R. D. BALDWIN, Assistant Examiner. 

1. THE COMBINATION, WITH A LADLE FOR TEEMING MOLTEN STEEL, WHICH LADLE INCLUDES SIDE AND BOTTOM WALLS, A POURING NOZZLE IN SAID BOTTOM WALL, AND A STOPPER FOR CONTROLLING FLOW THROUGH SAID NOZZLE, OF A VACUUM DEGASSING APPARATUS COMPRISING A PLURALITY OF SUPPORT MEANS DEPENDING FROM SAID LADLE, RESPECTIVE LOAD CELLS DEPENDING FROM SAID SUPPORT MEANS AND BEING DETACHABLE THEREFROM, A REFRACTORY LINED CHAMBER CARRIED BY SAID LOAD CELLS BENEATH SAID LADLE AND HAVING A FILLING NECK AT ITS TOP TELESCOPICALLY RECEIVING SAID NOZZLE, FLEXIBLE MEANS PROVIDING A SEAL BETWEEN SAID NOZZLE AND SAID NECK, A NOZZLE EXTENDING DOWNWARDLY FROM SAID CHAMBER, MEANS IN SAID SECOND-NAMED NOZZLE FOR CONTROLLING FLOW THERETHROUGH, A VACUUM PUMP AND A DRIVE THEREFOR, SUPPORT MEANS ON THE SIDE WALL OF SAID LADLE ABOVE SAID CHAMBER ON WHICH SAID PUMP AND DRIVE ARE MOUNTED, AND A VACUUM EXHAUST LINE EXTENDING DOWNWARDLY FROM SAID PUMP INTO SAID CHAMBER, SAID APPARATUS BEING SUPPORTED EXCLUSIVELY FROM THE WALLS OF SAID LADLE TO ENABLE THE LADLE AND APPARATUS TO BE MOVED FREELY ABOUT AS A UNIT IN ALL DIRECTIONS, SAID LOAD CELLS TRANSMITTING A CONTINUOUS INDICATION OF THE WEIGHT OF MATERIAL IN SAID CHAMBER. 